|Platform(s)||Windows, Linux, macOS, Solaris, BSD|
FCE Ultra Extended, typically shortened to FCEUX, is an open-source Famicom (NES) and Famicom Disk System (FDS) emulator. It began as an amalgamation of several FCE Ultra forks, designed to unify the then vast number of FCE Ultra branches with differing features. FCEUX has itself been forked, though mostly to increase the amount of platforms it is on, such as a GameCube and Wii port known as FCE Ultra GX.
Despite its extensive toolset, it is less accurate than other NES/FDS emulators like Nestopia, Mesen and puNES. However, thanks to FCEUmm being one of the forks it incorporates, it still has its uses as a highly compatible standalone emulator. It is recommended to download the latest AppVeyor build as the stable release is very old. It is also popular for developing new NES games, due to its excellent debugging tools, however, if you develop games/ROM hacks, be sure to test them on more accurate emulators, and/or with a flash cart on the real system to ensure compatibility.